Of course most of those are closed or semi closed so useless for commercial purposes...
Of course that won't save you if you go to servers that don't have reporting disabled so careful where you play.
Basically with each chat message there's a cryptographic payload proving that you are the sender, so reports can't be fabricated.
If you remove it on the server before sending it to other players (or remove it on your client before sending it to the server) you can't report the messages.
Also look into this and this for exploits:
Someone found the right way to phrase a report or are just relying on support to mess up on one of the many reports being sent to get them banned. It's not like the player being banned was on the same server as the people reporting them.
I didn't find any info about this exploit, and I thought it was related to chat reporting (being hate "speech" after all)